THORLABS BC207UV, Operating Manual

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BC207 Series
Chapter 6: Operation Instructions
Rev: 8.1, 10-Jan-2022
Page 136
© 2022 Thorlabs
This setting can be changed to manual, but this may affect the measurement.
By default the Clip Level of the Calculation Area is set to 1%. This is a reasonable value for
most applications and measurements. Lowering the clip level leads to increased calculation
area and noise level, this way increasing the measured the beam width.
Note
Setting the Clip Level of the Calculation Area for divergence measurements is not as critical as
for M
2
measurements. Increasing the Clip Level will give smaller beam widths but might cut the
beam profile.
Initial Settings
Independently from the user-defined settings, the following options are set automatically for
every divergence measurement.
Setting Parameter
Calculation Area Automatic
Auto Exposure On
Ambient Light Correction remains as set
Note
It is strongly recommended to run an ambient light correction prior to any measurement, and
then enable Ambient Light Correction.
Please be aware of the fact that ambient light correction is disabled any time the Beam Soft-
ware is started and/or the settings for
attenuation (filter wheel) are changed in the software.
6.3.8.4 Saving the Divergence Measurement Results
Besides the standard function "Save Divergence Measurement Results" the Thorlabs Beam
Software offers an automatic saving of beam profile data when a Divergence measurement is
executed.
For details, please see section Saving the M² Measurement Results .
Note
The Divergence measurement results cannot be saved as PDF Test Protocol, only as CSV,
TXT or XLS files.
6.3.8.5 Running the Divergence Measurement
The divergence measurement is designed to measure low divergent or convergent beam
propagation. Therefore, the measurement requires removing any focusing elements which pro-
duce a beam waist within the scan range.
Prior to starting the measurement, make sure that:
·
The beam is aligned properly - it should ideally remain centered with respect to the sensor
center over the entire scan range. See chapter
Beam Alignment for aligning the beam.
·
The ambient light is turned off or dimmed as far as possible. Ambient light may disturb the
measurement and should be avoided.
·
Reflections and interferences are avoided as far as possible.
·
The laser system is warmed up - depending on the source this might take up to 1 hour.
·
The laser output is spatially and temporally stable.
Start the measurement by clicking the Start button .
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